MAKING
1) In a pan, melt the butter. Toss in the chopped onion and saute for 5 minutes.
2) Add in the shredded lettuce and cook for 5 minutes.
3) Pour in the chicken stock.
4) Season the stock with salt and pepper. Cover the pan and allow to simmer for 10 minutes.
5) Next, add in the frozen peas. Cook them for 5 minutes till they are defrosted.
6) Allow the mixture to cool down slightly before transferring into a blender. Puree the mix.
7) Strain the soup through a very fine mesh or nylon sieve.
8) Transfer the soup into a soup tureen.
9) Mix in yoghurt, lemon juice and chopped mint.